One-piece dosing cap

ABSTRACT

The present invention is directed to a one-piece dosing cap comprising a top wall, side walls defining the top portion of a dosing compartment, and an attaching skirt extending from the base of the side walls, said skirt comprising substantially vertical walls and a stopping portion, characterized in that said dosing cap comprises at least one undercut portion. Preferably, the one-piece dosing cap of the present invention is manufactured by a one-step injection molding process. Also preferably, said cap comprises attachment means for securing, more preferably releasably securing said cap onto the neck of a container. More preferably, said attachment means are achieved by screw threads, which match cooperating screw threads of the container.

FIELD OF THE INVENTION

[0001] The present invention relates to dosing caps, typically thosewhich are used to dose home care or fabric care products.

BACKGROUND OF THE INVENTION

[0002] Plastic dosing caps for dosing treatment compositions in a dishor laundry washing solution are representative of the various dosingcaps to which the present invention can apply. Typically, such dosingcaps comprise a main dosing compartment, which is typically in the shapeof a cylinder, closed at the top by a top wall. This dosing compartmentis surrounded by an external skirt, extending outwardly therefrom, whichis provided with screw threads or other means for releasably securingsaid dosing cap onto the neck of a container, for example a bottle. Suchdosing caps are very easily manufactured by a injection molding processbecause they are typically made out of a thermoplastic resin, forexample a polyethylene or a polypropylene.

[0003] In such an injection molding process, the mold comprises at leasttwo parts: a first half which defines the outer surface of the cap,including the top wall. The other half acts like a plug into the firstouter half, and defines the inner surfaces of the cap. At the time thecap has been molded, the inner half of the mold is fitting into theouter half, but it then needs to be extracted therefrom, so that themold can be opened, and the molded cap can be ejected therefrom. For thecap to be properly ejected, it is preferable that the dosing compartmentbe slightly conical, so that the inner half of the injection mold canslide out of the outer half during the opening movement of the mold. Atleast, said dosing compartment cannot present any undercut, or as amaximum, a very limited undercut, which will allow the movable portionof the mold to slide therefrom by using the properties of flexibility ofthe thermoplastic material.

[0004] In addition to the above first limitation, there is a secondlimitation in the shape and dimensions of the dosing compartment. For agiven screwing diameter of the cap, the external diameter of the dosingcompartment cannot exceed a certain value, because there must besufficient space between the screw threads and the external surface ofthe dosing compartment. So for a given screwing diameter of the dosingcap, the internal diameter of the dosing compartment is limited and allthe sections along the height of the dosing compartment must be smallerthan the first section at the bottom of said dosing compartment (at themouth of the dosing compartment).

[0005] Given the above limitations, three solutions are typicallyavailable in the prior art. Most often, a first solution to increase thedosing volume without creating an undercut is to increase the height ofthe dosing cylinder, which means increasing the global height of thedosing cap. However, this solution has a major disadvantage: thecontainers will require more space on the shelves, and the shelf costper unit will be increased, which has a direct influence on the sellingprice of the product, thus being clearly undesirable to the consumer.Alternatively, to increasing the height of the of the top portion of thecap, it is possible to increase the dosing volume by increasing thelength of the dosing portion which is hanging into the bottle. However,with this solution, the mouth of the dosing cylinder is constantlyhanging into the product: so, when the consumer opens the bottle, thedosing portion of the cap is always dripping with product, which makesthe whole package look messy, and is thus particularly undesirable.

[0006] A second solution known from the prior art consists in moldingthe cap into two separate parts which are then assembled. The first partcomprises the base portion of the turret together with the skirt and itsattaching means. The other part which is molded separately comprises thetop portion of the dosing cylinder with its top wall. The top portion ofthe dosing cylinder can be designed with a greater diameter than thebase portion, as long as it does not itself comprise an undercut. Then,both parts are assembled, and the final dosing cap comprises an undercutwhich could not have been molded in a single step injection moldingprocess. However, making the cap into two separate parts and thenassembling them is a very expensive solution to the problem of molding acap that comprises an undercut. Indeed, this requires double tooling andmachinery, double space in the plant for these machines and optionallyfor storing the parts, supplemental assembling machinery, and more timeto produce a finished dosing cap.

[0007] A third solution consists in molding the cap in a one stepinjection molding process, by using a collapsible core which molds allthe inner surfaces of the dosing cylinder, i.e. both the bottom portion,and also the top portion which has a greater internal diameter. At theend of the injection molding cycle, the core retracts, so that itsundercut portion can be ejected through the bottom part of the dosingcylinder which has a restricted diameter. A major disadvantage inmolding a dosing cap with undercut using collapsible cores, is thatthese collapsible cores are very fragile, they are worn out very easily,and thus, they must be changed frequently. Of course, this dramaticallyincreases the production costs since such collapsible cores areexpensive, and also because the production must be stopped each time thecore needs to be changed, and the cycle times are longer.

[0008] It is therefore one main object of the present invention toprovide a cap with high dosing volume, which is not too high, and can bemade in a cheap way.

[0009] It is another object of the present invention to provide aprocess for molding such a cap, which is a single step injection moldingprocess without collapsible core, hence its low cost.

SUMMARY OF THE INVENTION

[0010] The present invention is directed to a one-piece dosing capcomprising a top wall, side walls defining the top portion of a dosingcompartment, and an attaching skirt extending from the base of the sidewalls, said skirt comprising substantially vertical walls and a stoppingportion, characterized in that said dosing cap comprises at least oneundercut portion. Preferably, the one-piece dosing cap of the presentinvention is manufactured by a one-step injection molding process. Alsopreferably, said cap comprises attachment means for securing, morepreferably releasably securing said cap onto the neck of a container.More preferably, said attachment means are achieved by screw threads,which match cooperating screw threads of the container.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention will now be explained in detail with reference tothe accompanying drawings, in which:

[0012]FIG. 1 is a profile cut view showing a dosing cap according to theprior art, wherein the height has been increased in order to increasethe dosing volume without having an undercut.

[0013]FIG. 2A is a profile cut view of the cap according to the presentinvention, showing the cap in open position, as positioned in the moldduring the injection molding process.

[0014]FIG. 2B is a profile cut view of the cap according to the presentinvention, showing the cap in closed position, as positioned in the moldat the end of the injection molding process, after both parts have beensealed to finish the cap.

[0015]FIG. 2C is a profile cut view of the cap according to the presentinvention, showing the cap in closed position, and secured onto the neckof a container.

[0016]FIG. 2D is a profile view showing the outside of a dosing capaccording to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The Dosing Cap

[0018] The dosing cap (1) according to the present invention comprises atop wall (13) and side walls (20) defining the top portion (15) of adosing compartment (10). The dosing cap (1) further comprises anattaching skirt (11) with attachment means (12) which extends downwardlyfrom the base of the side walls (20), as shown for example in FIG. 2B.The skirt (11) comprises substantially vertical walls with attachmentmeans (12).

[0019] It is an essential feature of the present invention that saidattaching skirt (11) comprises a stopping portion (21) extendinginwardly to the inside of the cap, thus partially closing the topportion (15) of the dosing compartment (10). This stopping portion (21)is substantially horizontal, is rigid, and has such a surface that itcreates at least one undercut portion (21) together with the top portion(15) of the dosing compartment (10). The role of such a stopping portion(21) is to stop the cap in the right position when closing the neck of acorresponding container, by contacting the top edge of the neck of saidcontainer, as shown for example in FIG. 2C. This is especially importantwhen the cap is deep and must be attached to a short neck. The attachingskirt (11) extends outwardly all around the periphery of the bottomportion (14) of the dosing cylinder, as shown in FIGS. 2B and 2C. Saidskirt (11) comprises attachment means (12) for the cap to be securedonto the neck of a container, which are preferably located on theinternal surface of the skirt (11) walls, such that once secured ontothe container, the skirt (11) surrounds the neck of said container.However, the attachment means (12) can alternatively be placed onto theexternal surface of the skirt (11), such that the dosing cap (1) can besecured onto the neck of a container having internal cooperatingattachment means (12). In a preferred embodiment, the attachment means(12) are achieved by one or more screw threads (12). Alternatively, theattachment means (12) are achieved by ribs and/or grooves which,together with cooperating ribs and/or grooves of the container neck,constitute clipping or bayonet attachment means (12).

[0020] The dosing cap (1) can have any suitable shape, but in thefollowing description, only the preferred embodiment where the cap iscylindrical—or slightly conical—will be described.

[0021] In a preferred embodiment of the invention and as shown in theattached figures, said dosing compartment (10) comprises a bottomportion (14) in addition to the top portion (15). Said bottom portionextends downwardly from the inner edges of the stopping portion (21) asshown in FIG. 2B. Said bottom portion (14) is open at its base so as toform a pouring spout (16). Top and bottom portions of the dosingcompartment are molded as one single unitary piece, and linked by alinking portion, for example a hinge portion (18), as shown in FIGS. 2Ato 2C, so that the whole cap is made out of one single piece.

[0022] The materials suitable for making a dosing cap (1) according tothe present invention include, but are not limited to thermoplasticresins, for example polyethylene or polypropylene, or elastomericmaterials such as for example synthetic rubber. The dosing cap (1) canbe made out of several different plastic materials, or the same plasticmaterial into which different additives are incorporated, for exampledifferent colours.

[0023] Dosing caps according to the present invention are typically tobe used for dosing of cleaning or detergent compositions for home careor fabric care products, including but not limited to soaps, laundrydetergents, colour care products, dye care products, bleach orhypochlorite additives . . . etc. These products can have any form, aslong as they are flowable enough to be dosed by using a dosing cap (1).For example they can be liquids, flakes, powders, granules, gels or amixture thereof.

[0024] In a preferred embodiment, the dosing cap (1) comprises a meansfor indicating to the consumer what is the amount of product to pourinto the dosing cap (1), in order to make a complete dose. For example,this can be achieved by putting a mark (rib or groove) on the internalsurface of the dosing compartment.

[0025] The Process

[0026] A dosing cap according to the present invention is made out ofthermoplastic resin, or a thermoplastic elastomer. Such caps aremanufactured by using an injection molding process. Such processes arewell know in the art, and will not be described further in thisdescription for clarity purposes. The dosing cap of the presentinvention is made out of one piece, and requires only one mold cavityfor its manufacture. The injection molded process can be a mono, multi,or co-injection molding process, depending on the number of differentmaterials that are chosen to make the cap.

[0027] Firstly, the cap is molded in open position, as shown in FIG. 2A,such that none of the molded parts contains an undercut. This willprevent the need for using collapsible cores which are usually worn outeasily and thus quite expensive to use for large production series.

[0028] Secondly, at the end of the molding cycle, the mold opens and thecap is partially ejected. At this point in time, the cap (1) ispreferably closed in the mold by pivoting the top (14) and bottom (15)portions of the dosing compartment (10) around the hinge portion (18).Techniques for folding or closing pieces in an injection mold are wellknown in the art. Alternatively, the cap can be ejected from theinjection mold in the open position, and be closed and sealed later onthe production line.

[0029] Thirdly, after having been folded and closed, the bottom (14) andtop (15) portions of the dosing compartment (10) are locked together, soas to finish the cap (1). Any suitable technique for securing said top(14) and bottom (15) portions of the dosing compartment (10) can beused, as long as the cap thus formed is leaktight. This techniqueinclude, but are not limited to mechanical bounding, heat sealing,ultrasonic sealing, spin-welding, gluing with or without using anadditive . . . etc.

[0030] From the above, it will be easily understood that one essentialfeature of a cap according to the present invention is that said cap ismade out of one single piece, whatever the complexity of its shape, andwhatever the size of the undercut created by the stopping portion (21)of the skirt.

1. A one-piece dosing cap (1) comprising a top wall (13), side walls(20) defining the top portion (15) of a dosing compartment (10), and anattaching skirt (11) extending from the base of the side walls (20),said skirt comprising substantially vertical walls and a stoppingportion (21), characterized in that said dosing cap (10) comprises atleast one undercut portion.
 2. A cap (1) according to claim 1 , whereinthe dosing compartment (10) comprises a bottom portion (14) extendingdownwardly from the inner edges of the stopping portion (21) of theattaching skirt (11).
 3. A cap (1) according to claim 2 , wherein saidattaching skirt (11) comprises attachment means (12) for securing saidcap (1) onto the neck of a container.
 4. A cap (1) according to claim 3, wherein said attachment means (12) is achieved by screw threads.
 5. Acap (1) according to claim 3 , wherein said attachment means (12) isachieved by ribs and/or grooves of the skirt, which clip ontocorresponding grooves and/or ribs of the neck of a container.
 6. A cap(1) according to any of the preceding claims, which is made by aone-step injection molding process.
 7. A cap (1) according to claim 6 ,wherein said injection-molding process is a co-injection moldingprocess.
 8. A process of making a cap (1) according to any of thepreceding claims, characterized in that it comprises the steps of: (i)molding a plastic cap in two halves attached by at least one portion, inopen position; (ii) ejecting said two attached halves from the injectionmold; (iii) closing said two attached halves and sealing them to make aone-piece dosing cap as described in the preceding claims.
 9. A processaccording to claim 8 , wherein the sealing of the two halves to finishthe dosing cap is achieved by heat sealing.